keepalived的安装和配置

第一步：master和backup都进行安装keepalived

 yum -y install keepalived

第二步：配置keepalived

①备份主备服务器的配置文件

shell > cd /etc/keepalived
shell > cp keepalived.conf keepalived.conf_bak

②分别修改主备服务器配置文件

master

! Configuration File for keepalived
global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    #master默认只需要修改使用VIP即可
    virtual_ipaddress {
        10.1.1.6
    }
}

slave

! Configuration File for keepalived
global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_instance VI_1 {
    #修改工作模式为备
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    #注意修改VIP
    virtual_ipaddress {
        10.1.1.6
    }
}

③分别按照顺序启动主服务器和备服务器的keepalived

service keepalived start

④查看主备服务器的网卡信息

ip a s

示例配置文件

! Configuration File for keepalived
#发送邮件的配置
global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
#vrrp协议的配置
vrrp_instance VI_1 {
    #工作模式
    state MASTER
    #监听的网卡
    interface eth0
    #虚拟路由id 需要和备服务器一致
    virtual_router_id 51
    #权重 优先级
    priority 100
    #vrrp包的发送周期  1s
    advert_int 1
    #权限验证
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    #需要绑定切换的VIP
    virtual_ipaddress {
        192.168.200.16
        192.168.200.17
        192.168.200.18
    }
}

非抢占模式

①nopreempt

在主备服务器的配置文件，vrrp_instance段中

②设置state工作模式为BACKUP两个keepalived节点都启动后，默认都是BACKUP状态，双方在发送组播信息后，会根据优先级来选举一个MASTER出来。由于两者都配置了nopreempt，所以MASTER从故障中恢复后，不会抢占vip。这样会避免VIP切换可能造成的服务延迟。

单播模式

master上配置

#在vrrp_instace段中加入
#本地IP
unicast_src_ip 10.1.1.3
unicast_peer {
    #对象IP  发送vrrp包给备服务器
    10.1.1.4
}

slave上配置

#在vrrp_instace段中加入
#本地IP
unicast_src_ip 10.1.1.4
unicast_peer {
    #对象IP  发送vrrp包给备服务器
    10.1.1.3
}